text: #include <vnet/vnet.h>
  #include <vnet/plugin/plugin.h>
  #include <vpp/app/version.h>
  #include <vnet/session/session.h>
  #include <vnet/session/segment_manager.h>
  #include <vnet/session/application.h>
  
  #define SEG_MGR_TEST_I(_cond, _comment, _args...)               \
  ({                                                              \
    int _evald = (_cond);                                         \
    if (!(_evald)) {                                              \
      fformat(stderr, "FAIL:%d: " _comment "\n",                  \
              __LINE__, ##_args);                                 \
    } else {                                                      \
      fformat(stderr, "PASS:%d: " _comment "\n",                  \
              __LINE__, ##_args);                                 \
    }                                                             \
    _evald;                                                       \
  })
  
  #define SEG_MGR_TEST(_cond, _comment, _args...)                 \
  {                                                               \
      if (!SEG_MGR_TEST_I(_cond, _comment, ##_args)) {            \
          return 1;                                               \
      }                                                           \
  }
  
  #define ST_DBG(_comment, _args...)                              \
      fformat(stderr,  _comment "\n",  ##_args);                  \
  
  #define SEGMENT_MANAGER_GET_INDEX_FROM_HANDLE(x) (x >> 32)
  
  /* placeholder callback functions */
  static void
  placeholder_session_reset_callback (session_t * s)
  {
    clib_warning ("called...");
  }
  
  static int
  placeholder_session_connected_callback (u32 app_index, u32 api_context,
  					session_t * s, session_error_t err)
  {
    clib_warning ("called...");
    return 0;
  }
  
  static int
  placeholder_add_segment_callback (u32 client_index, u64 segment_handle)
  {
    clib_warning ("called...");
    return 0;
  }
  
  static int
  placeholder_del_segment_callback (u32 client_index, u64 segment_handle)
  {
    clib_warning ("called...");
    return 0;
  }
  
  static void
  placeholder_session_disconnect_callback (session_t * s)
  {
    clib_warning ("called...");
  }
  
  static int
  placeholder_session_accept_callback (session_t * s)
  {
    clib_warning ("called...");
    return 0;
  }
  
  static int
  placeholder_server_rx_callback (session_t * s)
  {
    clib_warning ("called...");
    return -1;
  }
  
  /* *INDENT-OFF* */
  static session_cb_vft_t placeholder_session_cbs = {
    .session_reset_callback = placeholder_session_reset_callback,
    .session_connected_callback = placeholder_session_connected_callback,
    .session_accept_callback = placeholder_session_accept_callback,
    .session_disconnect_callback = placeholder_session_disconnect_callback,
    .builtin_app_rx_callback = placeholder_server_rx_callback,
    .add_segment_callback = placeholder_add_segment_callback,
    .del_segment_callback = placeholder_del_segment_callback,
  };
  /* *INDENT-ON* */
  
  static char *states_str[] = {
  #define _(sym,str) str,
    foreach_segment_mem_status
  #undef _
  };
  
  static u32 size_4KB = 4 << 10;
  static u32 size_8KB = 8 << 10;
  static u32 size_12KB = 12 << 10;
  static u32 size_16KB = 16 << 10;
  static u32 size_20KB = 20 << 10;
  static u32 size_32KB = 32 << 10;
  static u32 size_52KB = 52 << 10;
  static u32 size_64KB = 64 << 10;
  static u32 size_128KB = 128 << 10;
  static u32 size_1MB = 1 << 20;
  static u32 size_2MB = 2 << 20;
  
  
  static int
  segment_manager_test_pressure_1 (vlib_main_t * vm, unformat_input_t * input)
  {
    int rv;
    segment_manager_t *sm;
    fifo_segment_t *fs0, *fs;
    svm_fifo_t *rx_fifo, *tx_fifo;
    uword app_seg_size = size_2MB;
    u32 fifo_size = size_128KB;
    u64 options[APP_OPTIONS_N_OPTIONS];
    u8 data[size_128KB];
  
    memset (&options, 0, sizeof (options));
  
    vnet_app_attach_args_t attach_args = {
      .api_client_index = ~0,
      .options = options,
      .namespace_id = 0,
      .session_cb_vft = &placeholder_session_cbs,
      .name = format (0, "segment_manager_test_pressure_1"),
    };
  
    attach_args.options[APP_OPTIONS_SEGMENT_SIZE] = app_seg_size;
    attach_args.options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
    attach_args.options[APP_OPTIONS_RX_FIFO_SIZE] = fifo_size;
    attach_args.options[APP_OPTIONS_TX_FIFO_SIZE] = fifo_size;
    rv = vnet_application_attach (&attach_args);
    SEG_MGR_TEST ((rv == 0), "vnet_application_attach %d", rv);
  
    sm =
      segment_manager_get (SEGMENT_MANAGER_GET_INDEX_FROM_HANDLE
  			 (attach_args.segment_handle));
    SEG_MGR_TEST ((sm != 0), "segment_manager_get %p", sm);
  
    /* initial status : (0 / 2MB) */
    fs0 = segment_manager_get_segment (sm, 0);
    rv = fifo_segment_get_mem_status (fs0);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_NO_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
  
    /* allocate a fifo : 128KB x2 */
    rv = segment_manager_alloc_session_fifos (sm,
  					    vlib_get_thread_index (),
  					    &rx_fifo, &tx_fifo);
    SEG_MGR_TEST ((rv == 0), "segment_manager_alloc_session_fifos %d", rv);
  
    svm_fifo_set_size (rx_fifo, size_1MB);
    svm_fifo_set_size (tx_fifo, size_1MB);
  
    fs = segment_manager_get_segment (sm, rx_fifo->segment_index);
    SEG_MGR_TEST ((fs == fs0), "fs %p", fs);
  
    /* fill fifos (but not add chunks) */
    svm_fifo_enqueue (rx_fifo, fifo_size - 1, data);
    svm_fifo_enqueue (tx_fifo, fifo_size - 1, data);
  
    /* 256KB+ / 2048KB+ => ~12% */
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_NO_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    /* grow fifos */
    svm_fifo_enqueue (rx_fifo, fifo_size, data);
    svm_fifo_enqueue (rx_fifo, fifo_size, data);
    svm_fifo_enqueue (rx_fifo, fifo_size, data);
    svm_fifo_enqueue (tx_fifo, fifo_size, data);
    svm_fifo_enqueue (tx_fifo, fifo_size, data);
  
    /* 7 chunks : ~44% */
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_NO_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    /* grow fifos */
    svm_fifo_enqueue (tx_fifo, fifo_size, data);
    svm_fifo_enqueue (rx_fifo, fifo_size, data);
    svm_fifo_enqueue (tx_fifo, fifo_size, data);
  
    /* 10 chunks : 61% */
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_LOW_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    /* grow fifos */
    svm_fifo_enqueue (rx_fifo, fifo_size, data);
    svm_fifo_enqueue (rx_fifo, fifo_size, data);
    svm_fifo_enqueue (tx_fifo, fifo_size, data);
    svm_fifo_enqueue (tx_fifo, fifo_size, data);
  
    /* 14 chunks : 85% */
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_HIGH_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
  
    /* shrink fifos */
    svm_fifo_dequeue_drop (rx_fifo, fifo_size);
    svm_fifo_dequeue_drop (rx_fifo, fifo_size);
    svm_fifo_dequeue_drop (tx_fifo, fifo_size);
    svm_fifo_dequeue_drop (tx_fifo, fifo_size);
  
    /* 10 chunks : 63% */
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_LOW_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
  
    /* grow fifos */
    svm_fifo_enqueue (rx_fifo, fifo_size, data);
    svm_fifo_enqueue (rx_fifo, fifo_size, data);
    svm_fifo_enqueue (tx_fifo, fifo_size, data);
    svm_fifo_enqueue (tx_fifo, fifo_size, data);
  
    /* 14 chunks : 88% */
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_HIGH_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    svm_fifo_dequeue_drop (rx_fifo, fifo_size);
    svm_fifo_dequeue_drop (rx_fifo, fifo_size);
    svm_fifo_dequeue_drop (tx_fifo, fifo_size);
    svm_fifo_dequeue_drop (tx_fifo, fifo_size);
  
    /* 10 chunks : 63% */
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_LOW_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    /* shrink fifos */
    svm_fifo_dequeue_drop (rx_fifo, fifo_size);
    svm_fifo_dequeue_drop (rx_fifo, fifo_size);
    svm_fifo_dequeue_drop (rx_fifo, fifo_size);
    svm_fifo_dequeue_drop (rx_fifo, fifo_size);
    svm_fifo_dequeue_drop (tx_fifo, fifo_size);
    svm_fifo_dequeue_drop (tx_fifo, fifo_size);
    svm_fifo_dequeue_drop (tx_fifo, fifo_size);
    svm_fifo_dequeue_drop (tx_fifo, fifo_size);
  
    /* 2 chunks : 12% */
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_NO_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
  
    vnet_app_detach_args_t detach_args = {
      .app_index = attach_args.app_index,
      .api_client_index = ~0,
    };
    rv = vnet_application_detach (&detach_args);
    SEG_MGR_TEST ((rv == 0), "vnet_application_detach %d", rv);
  
    return 0;
  }
  
  static int
  segment_manager_test_pressure_2 (vlib_main_t * vm, unformat_input_t * input)
  {
    int rv, i;
    segment_manager_t *sm;
    fifo_segment_t *fs0, *fs;
    svm_fifo_t *rx_fifo, *tx_fifo;
    uword app_seg_size = size_2MB;
    u32 fifo_size = size_4KB;
    u64 options[APP_OPTIONS_N_OPTIONS];
    u8 data[size_4KB];
  
    memset (&options, 0, sizeof (options));
  
    vnet_app_attach_args_t attach_args = {
      .api_client_index = ~0,
      .options = options,
      .namespace_id = 0,
      .session_cb_vft = &placeholder_session_cbs,
      .name = format (0, "segment_manager_test_pressure_2"),
    };
  
    attach_args.options[APP_OPTIONS_SEGMENT_SIZE] = app_seg_size;
    attach_args.options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
    attach_args.options[APP_OPTIONS_RX_FIFO_SIZE] = fifo_size;
    attach_args.options[APP_OPTIONS_TX_FIFO_SIZE] = fifo_size;
    rv = vnet_application_attach (&attach_args);
    SEG_MGR_TEST ((rv == 0), "vnet_application_attach %d", rv);
  
    sm =
      segment_manager_get (SEGMENT_MANAGER_GET_INDEX_FROM_HANDLE
  			 (attach_args.segment_handle));
    SEG_MGR_TEST ((sm != 0), "segment_manager_get %p", sm);
  
    /* initial status : (0 / 2MB) */
    fs0 = segment_manager_get_segment (sm, 0);
    rv = fifo_segment_get_mem_status (fs0);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_NO_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
  
    /* allocate fifos : 4KB x2 */
    rv = segment_manager_alloc_session_fifos (sm,
  					    vlib_get_thread_index (),
  					    &rx_fifo, &tx_fifo);
    SEG_MGR_TEST ((rv == 0), "segment_manager_alloc_session_fifos %d", rv);
  
    svm_fifo_set_size (rx_fifo, size_1MB);
    svm_fifo_set_size (tx_fifo, size_1MB);
  
    /* fill fifos (but not add chunks) */
    svm_fifo_enqueue (rx_fifo, fifo_size - 1, data);
    svm_fifo_enqueue (tx_fifo, fifo_size - 1, data);
  
    fs = segment_manager_get_segment (sm, rx_fifo->segment_index);
  
    /* grow fifos */
    for (i = 0; i < 509; ++i)
      {
        svm_fifo_enqueue (rx_fifo, fifo_size, data);
        svm_fifo_enqueue (tx_fifo, fifo_size, data);
      }
  
    /* 100% of 2MB */
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_HIGH_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    /* this fifo growth is expected to fail */
    rv = svm_fifo_enqueue (rx_fifo, fifo_size, data);
    SEG_MGR_TEST ((rv == SVM_FIFO_EGROW), "svm_fifo_enqueue %d", rv);
  
    /* shrink fifos */
    for (i = 0; i < 20; ++i)
      {
        svm_fifo_dequeue_drop (rx_fifo, fifo_size);
        svm_fifo_dequeue_drop (tx_fifo, fifo_size);
      }
  
    /* 489 chunks : 96%, it is high-pressure level
     * but the reached-mem-limit record is not reset
     * so the no-memory state lasts.
     */
    /*
     rv = fifo_segment_get_mem_status (fs);
     SEG_MGR_TEST ((rv == MEMORY_PRESSURE_NO_MEMORY),
  		 "fifo_segment_get_mem_status %s", states_str[rv]);
    */
  
    /* shrink fifos */
    for (i = 0; i < 133; ++i)
      {
        svm_fifo_dequeue_drop (rx_fifo, fifo_size);
      }
  
    /* 356 chunks : 70% of 2MB */
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_LOW_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    /* shrink fifos */
    for (i = 0; i < 360; ++i)
      {
        svm_fifo_dequeue_drop (rx_fifo, fifo_size);
        svm_fifo_dequeue_drop (tx_fifo, fifo_size);
      }
  
    /* 2 chunks : 3% of 2MB */
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_NO_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
  
    vnet_app_detach_args_t detach_args = {
      .app_index = attach_args.app_index,
      .api_client_index = ~0,
    };
    rv = vnet_application_detach (&detach_args);
    SEG_MGR_TEST ((rv == 0), "vnet_application_detach %d", rv);
  
    return 0;
  }
  
  static int
  segment_manager_test_fifo_balanced_alloc (vlib_main_t * vm,
  					  unformat_input_t * input)
  {
    int rv, i, fs_index;
    segment_manager_t *sm;
    fifo_segment_t *fs[4];
    svm_fifo_t *rx_fifo[4], *tx_fifo[4];
    uword app_seg_size = size_2MB;
    u32 fifo_size = size_4KB;
    u64 options[APP_OPTIONS_N_OPTIONS];
    u8 data[size_4KB];
  
    memset (&options, 0, sizeof (options));
  
    vnet_app_attach_args_t attach_args = {
      .api_client_index = ~0,
      .options = options,
      .namespace_id = 0,
      .session_cb_vft = &placeholder_session_cbs,
      .name = format (0, "segment_manager_test_fifo_balanced_alloc"),
    };
  
    attach_args.options[APP_OPTIONS_SEGMENT_SIZE] = app_seg_size;
    attach_args.options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
    attach_args.options[APP_OPTIONS_RX_FIFO_SIZE] = fifo_size;
    attach_args.options[APP_OPTIONS_TX_FIFO_SIZE] = fifo_size;
    rv = vnet_application_attach (&attach_args);
    SEG_MGR_TEST ((rv == 0), "vnet_application_attach %d", rv);
  
    sm =
      segment_manager_get (SEGMENT_MANAGER_GET_INDEX_FROM_HANDLE
  			 (attach_args.segment_handle));
    SEG_MGR_TEST ((sm != 0), "segment_manager_get %p", sm);
  
    /* initial status : (0 / 2MB) */
    fs[0] = segment_manager_get_segment (sm, 0);
    rv = fifo_segment_get_mem_status (fs[0]);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_NO_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    /* allocate fifos : 4KB x2 */
    rv = segment_manager_alloc_session_fifos (sm,
  					    vlib_get_thread_index (),
  					    &rx_fifo[0], &tx_fifo[0]);
    SEG_MGR_TEST ((rv == 0), "segment_manager_alloc_session_fifos %d", rv);
    SEG_MGR_TEST ((rx_fifo[0]->segment_index == 0),
  		"segment_index %d", rx_fifo[0]->segment_index);
    SEG_MGR_TEST ((tx_fifo[0]->segment_index == 0),
  		"segment_index %d", tx_fifo[0]->segment_index);
  
    /* grow fifos */
    svm_fifo_set_size (rx_fifo[0], size_1MB);
    for (i = 0; i < 200; ++i)
      {
        svm_fifo_enqueue (rx_fifo[0], fifo_size, data);
      }
  
    /* add another 2MB segment */
    fs_index = segment_manager_add_segment (sm, size_2MB, 0);
    SEG_MGR_TEST ((fs_index == 1), "fs_index %d", fs_index);
  
    /* allocate fifos : 4KB x2
     * expected to be allocated on the newer segment,
     * because the usage of the first segment is high.
     */
    rv = segment_manager_alloc_session_fifos (sm,
  					    vlib_get_thread_index (),
  					    &rx_fifo[1], &tx_fifo[1]);
    SEG_MGR_TEST ((rv == 0), "segment_manager_alloc_session_fifos %d", rv);
    SEG_MGR_TEST ((rx_fifo[1]->segment_index == 1),
  		"segment_index %d", rx_fifo[1]->segment_index);
    SEG_MGR_TEST ((tx_fifo[1]->segment_index == 1),
  		"segment_index %d", tx_fifo[1]->segment_index);
  
    /* allocate fifos : 4KB x2
     * expected to be allocated on the newer segment.
     */
    rv = segment_manager_alloc_session_fifos (sm,
  					    vlib_get_thread_index (),
  					    &rx_fifo[2], &tx_fifo[2]);
    SEG_MGR_TEST ((rv == 0), "segment_manager_alloc_session_fifos %d", rv);
    SEG_MGR_TEST ((rx_fifo[2]->segment_index == 1),
  		"segment_index %d", rx_fifo[2]->segment_index);
    SEG_MGR_TEST ((tx_fifo[2]->segment_index == 1),
  		"segment_index %d", tx_fifo[2]->segment_index);
  
    /* grow fifos, so the usage of the secong segment becomes
     * higher than the first one.
     */
    svm_fifo_set_size (rx_fifo[1], size_1MB);
    for (i = 0; i < 400; ++i)
      {
        svm_fifo_enqueue (rx_fifo[1], fifo_size, data);
      }
  
    /* allocate fifos : 4KB x2
     * expected to be allocated on the first segment.
     */
    rv = segment_manager_alloc_session_fifos (sm,
  					    vlib_get_thread_index (),
  					    &rx_fifo[3], &tx_fifo[3]);
    SEG_MGR_TEST ((rv == 0), "segment_manager_alloc_session_fifos %d", rv);
    SEG_MGR_TEST ((rx_fifo[3]->segment_index == 0),
  		"segment_index %d", rx_fifo[3]->segment_index);
    SEG_MGR_TEST ((tx_fifo[3]->segment_index == 0),
  		"segment_index %d", tx_fifo[3]->segment_index);
  
  
  
    vnet_app_detach_args_t detach_args = {
      .app_index = attach_args.app_index,
      .api_client_index = ~0,
    };
    rv = vnet_application_detach (&detach_args);
    SEG_MGR_TEST ((rv == 0), "vnet_application_detach %d", rv);
  
    return 0;
  }
  
  /* disabled until fifo tuning and memory pressure are properly working */
  __clib_unused static int
  segment_manager_test_fifo_ops (vlib_main_t *vm, unformat_input_t *input)
  {
    int rv, i;
    segment_manager_t *sm;
    fifo_segment_t *fs;
    svm_fifo_t *rx_fifo, *tx_fifo;
    uword app_seg_size = size_2MB, most_grown = 0;
    u32 fifo_size = size_4KB;
    u32 max_dequeue = 0;
    u64 options[APP_OPTIONS_N_OPTIONS];
    u8 data[size_128KB];
  
    memset (&options, 0, sizeof (options));
  
    vnet_app_attach_args_t attach_args = {
      .api_client_index = ~0,
      .options = options,
      .namespace_id = 0,
      .session_cb_vft = &placeholder_session_cbs,
      .name = format (0, "segment_manager_test_pressure_1"),
    };
  
    attach_args.options[APP_OPTIONS_SEGMENT_SIZE] = app_seg_size;
    attach_args.options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
    attach_args.options[APP_OPTIONS_RX_FIFO_SIZE] = fifo_size;
    attach_args.options[APP_OPTIONS_TX_FIFO_SIZE] = fifo_size;
    rv = vnet_application_attach (&attach_args);
    SEG_MGR_TEST ((rv == 0), "vnet_application_attach %d", rv);
  
    sm =
      segment_manager_get (SEGMENT_MANAGER_GET_INDEX_FROM_HANDLE
  			 (attach_args.segment_handle));
    SEG_MGR_TEST ((sm != 0), "segment_manager_get %p", sm);
  
    /* initial status : (0 / 2MB) */
    fs = segment_manager_get_segment (sm, 0);
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_NO_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    /* allocate fifos : 4KB x2 */
    rv = segment_manager_alloc_session_fifos (sm,
  					    vlib_get_thread_index (),
  					    &rx_fifo, &tx_fifo);
    SEG_MGR_TEST ((rv == 0), "segment_manager_alloc_session_fifos %d", rv);
  
    /* check the initial fifo size : 4KB */
    rv = svm_fifo_size (rx_fifo);
    SEG_MGR_TEST ((rv == size_4KB), "svm_fifo_size %d", rv);
  
    /* fill 4KB */
    rv = svm_fifo_enqueue (rx_fifo, size_4KB, data);
    SEG_MGR_TEST ((rv == size_4KB), "svm_fifo_enqueue %d", rv);
    max_dequeue = svm_fifo_max_dequeue (rx_fifo);
    SEG_MGR_TEST ((max_dequeue == size_4KB), "max_dequeue %u", max_dequeue);
  
    /* grow the fifo size : 4KB -> 8KB */
    svm_fifo_set_size (rx_fifo, size_8KB);
    rv = svm_fifo_size (rx_fifo);
    SEG_MGR_TEST ((rv == size_8KB), "svm_fifo_size %d", rv);
  
    /* verify that fifo cannot grow larger than the fifo size */
    /* 4KB + 8KB > 8KB, so only 4KB is queued */
    rv = svm_fifo_enqueue (rx_fifo, size_8KB, data);
    SEG_MGR_TEST ((rv == size_4KB), "svm_fifo_enqueue %d", rv);
    max_dequeue = svm_fifo_max_dequeue (rx_fifo);
    SEG_MGR_TEST ((max_dequeue == size_8KB), "max_dequeue %u", max_dequeue);
  
    /* grow the fifo size : 8KB -> 16KB */
    svm_fifo_set_size (rx_fifo, size_16KB);
  
    /* 8KB + 4KB = 12KB */
    svm_fifo_enqueue (rx_fifo, size_4KB, data);
    max_dequeue = svm_fifo_max_dequeue (rx_fifo);
    SEG_MGR_TEST ((max_dequeue == size_12KB), "max_dequeue %u", max_dequeue);
  
    /* grow the fifo size : 16KB -> 32KB */
    svm_fifo_set_size (rx_fifo, size_32KB);
  
    /* 12KB + 8KB = 20KB */
    svm_fifo_enqueue (rx_fifo, size_8KB, data);
    max_dequeue = svm_fifo_max_dequeue (rx_fifo);
    SEG_MGR_TEST ((max_dequeue == size_20KB), "max_dequeue %u", max_dequeue);
  
    /* grow the fifo size : 32KB -> 64KB */
    svm_fifo_set_size (rx_fifo, size_64KB);
  
    /* 20KB + 32KB = 52KB */
    svm_fifo_enqueue (rx_fifo, size_32KB, data);
    max_dequeue = svm_fifo_max_dequeue (rx_fifo);
    SEG_MGR_TEST ((max_dequeue == size_52KB), "max_dequeue %u", max_dequeue);
  
    /* bulk enqueue */
    for (i = 0; i < 55; ++i)
      {
        svm_fifo_set_size (rx_fifo, svm_fifo_size (rx_fifo) + size_32KB);
        svm_fifo_enqueue (rx_fifo, size_32KB, data);
      }
    max_dequeue = svm_fifo_max_dequeue (rx_fifo);
    SEG_MGR_TEST ((max_dequeue == (size_52KB + size_32KB * 55)),
  		"max_dequeue %u", max_dequeue);
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_HIGH_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
    most_grown = svm_fifo_size (rx_fifo);
  
    /* dequeue */
    svm_fifo_dequeue_drop (rx_fifo, size_20KB);
    svm_fifo_dequeue_drop (rx_fifo, size_32KB);
  
    /* bulk dequeue */
    for (i = 0; i < 20; ++i)
      svm_fifo_dequeue_drop (rx_fifo, size_32KB);
    max_dequeue = svm_fifo_max_dequeue (rx_fifo);
    SEG_MGR_TEST ((max_dequeue == (size_32KB * 35)), "max_dequeue %u",
  		max_dequeue);
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_LOW_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    /* bulk dequeue */
    for (i = 0; i < 10; ++i)
      svm_fifo_dequeue_drop (rx_fifo, size_32KB);
    max_dequeue = svm_fifo_max_dequeue (rx_fifo);
    SEG_MGR_TEST ((max_dequeue == (size_32KB * 25)), "max_dequeue %u",
  		max_dequeue);
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_NO_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    /* bulk enqueue */
    for (i = 0; i < 30; ++i)
      svm_fifo_enqueue (rx_fifo, size_32KB, data);
    max_dequeue = svm_fifo_max_dequeue (rx_fifo);
    SEG_MGR_TEST ((max_dequeue == (size_32KB * 55)), "max_dequeue %u",
  		max_dequeue);
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_HIGH_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    /* bulk dequeue */
    for (i = 0; i < 20; ++i)
      svm_fifo_dequeue_drop (rx_fifo, size_32KB);
    max_dequeue = svm_fifo_max_dequeue (rx_fifo);
    SEG_MGR_TEST ((max_dequeue == (size_32KB * 35)), "max_dequeue %u",
  		max_dequeue);
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_LOW_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    /* bulk dequeue */
    for (i = 0; i < 35; ++i)
      svm_fifo_dequeue_drop (rx_fifo, size_32KB);
    max_dequeue = svm_fifo_max_dequeue (rx_fifo);
    SEG_MGR_TEST ((max_dequeue == 0), "max_dequeue %u", max_dequeue);
    rv = fifo_segment_get_mem_status (fs);
    SEG_MGR_TEST ((rv == MEMORY_PRESSURE_NO_PRESSURE),
  		"fifo_segment_get_mem_status %s", states_str[rv]);
  
    /* (virtual) fifo size is still large as it is not updated */
    SEG_MGR_TEST ((rx_fifo->shr->size == most_grown), "rx_fifo->size %u",
  		rx_fifo->shr->size);
  
    vnet_app_detach_args_t detach_args = {
      .app_index = attach_args.app_index,
      .api_client_index = ~0,
    };
    rv = vnet_application_detach (&detach_args);
    SEG_MGR_TEST ((rv == 0), "vnet_application_detach %d", rv);
  
    return 0;
  }
  
  static int
  segment_manager_test_prealloc_hdrs (vlib_main_t * vm,
  				    unformat_input_t * input)
  {
    u32 fifo_size = size_4KB, prealloc_hdrs, sm_index, fs_index;
    u64 options[APP_OPTIONS_N_OPTIONS];
    uword app_seg_size = size_2MB * 2;
    segment_manager_t *sm;
    fifo_segment_t *fs;
    int rv;
  
    memset (&options, 0, sizeof (options));
  
    vnet_app_attach_args_t attach_args = {
      .api_client_index = ~0,
      .options = options,
      .namespace_id = 0,
      .session_cb_vft = &placeholder_session_cbs,
      .name = format (0, "segment_manager_test_prealloc_hdrs"),
    };
  
    prealloc_hdrs = 64;
  
    attach_args.options[APP_OPTIONS_SEGMENT_SIZE] = app_seg_size;
    attach_args.options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
    attach_args.options[APP_OPTIONS_RX_FIFO_SIZE] = fifo_size;
    attach_args.options[APP_OPTIONS_TX_FIFO_SIZE] = fifo_size;
    attach_args.options[APP_OPTIONS_PREALLOC_FIFO_HDRS] = prealloc_hdrs;
  
    rv = vnet_application_attach (&attach_args);
    vec_free (attach_args.name);
  
    SEG_MGR_TEST ((rv == 0), "vnet_application_attach %d", rv);
  
    segment_manager_parse_segment_handle (attach_args.segment_handle, &sm_index,
  					&fs_index);
    sm = segment_manager_get (sm_index);
  
    SEG_MGR_TEST ((sm != 0), "seg manager is valid", sm);
  
    fs = segment_manager_get_segment (sm, fs_index);
    SEG_MGR_TEST (fifo_segment_num_free_fifos (fs) == prealloc_hdrs,
  		"prealloc should be %u", prealloc_hdrs);
  
    vnet_app_detach_args_t detach_args = {
      .app_index = attach_args.app_index,
      .api_client_index = ~0,
    };
    rv = vnet_application_detach (&detach_args);
    SEG_MGR_TEST ((rv == 0), "vnet_application_detach %d", rv);
    return 0;
  }
  
  static clib_error_t *
  segment_manager_test (vlib_main_t * vm,
  		      unformat_input_t * input, vlib_cli_command_t * cmd_arg)
  {
    int res = 0;
  
    vnet_session_enable_disable (vm, 1);
  
    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
      {
        if (unformat (input, "pressure_levels_1"))
  	res = segment_manager_test_pressure_1 (vm, input);
        else if (unformat (input, "pressure_levels_2"))
  	res = segment_manager_test_pressure_2 (vm, input);
        else if (unformat (input, "alloc"))
  	res = segment_manager_test_fifo_balanced_alloc (vm, input);
        else if (unformat (input, "prealloc_hdrs"))
  	res = segment_manager_test_prealloc_hdrs (vm, input);
  
        else if (unformat (input, "all"))
  	{
  	  if ((res = segment_manager_test_pressure_1 (vm, input)))
  	    goto done;
  	  if ((res = segment_manager_test_pressure_2 (vm, input)))
  	    goto done;
  	  if ((res = segment_manager_test_fifo_balanced_alloc (vm, input)))
  	    goto done;
  	  if ((res = segment_manager_test_prealloc_hdrs (vm, input)))
  	    goto done;
  	}
        else
  	break;
      }
  
  done:
    if (res)
      return clib_error_return (0, "Segment manager unit test failed.");
    return 0;
  }
  
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (tcp_test_command, static) =
  {
    .path = "test segment-manager",
    .short_help = "test segment manager [pressure_levels_1]"
                  "[pressure_level_2][alloc][fifo_ops][prealloc_hdrs][all]",
    .function = segment_manager_test,
  };
  
  /*
   * fd.io coding-style-patch-verification: ON
   *
   * Local Variables:
   * eval: (c-set-style "gnu")
   * End:
   */
  